JP6582853B2 - Post-processing apparatus and image forming system - Google Patents

Description

  The present invention relates to a post-processing apparatus and an image forming system.

  2. Description of the Related Art Conventionally, a post-processing apparatus having a folding function of inserting a sheet with a folding knife between a pair of folding rollers to crease the sheet is known. As the post-processing apparatus, there is also proposed an apparatus in which a comb-like portion having irregularities is formed on a folding knife and the portion is inserted between a pair of folding rollers (see Patent Document 1). According to such a post-processing apparatus, when the folding knife is inserted and pulled out, the contact area between the pair of folding rollers can be reduced and the driving load of the folding knife can be reduced.

  Furthermore, aiming at the same effect, what provided the unevenness | corrugation in the roller axial direction with respect to a pair of folding roller is also proposed (refer patent document 2).

JP 2008-7297 A JP 2008-247535 A

  However, in the apparatuses described in Patent Documents 1 and 2, the fold-in timing of the sheet folding portion may differ in the width direction of the sheet with respect to the nip portion of the pair of folding rollers. It will cause the occurrence of. FIG. 12 is a schematic plan view for explaining the cause of occurrence of wrinkles. As shown in FIG. 12, the folding knife Fn has irregularities, and the convex portion 42 of the folding knife is located at one end E1 of the paper, but the concave portion 41 is located at the other end E2. Suppose that In this case, the entry timing of the other end E2 of the sheet located in the recess 41 may be delayed from other parts such as the end E1 of the sheet, which may cause wrinkles and tears.

  The present invention has been made to solve such a problem, and an object of the present invention is to reduce the driving load of the folding knife and to prevent the paper from being wrinkled or torn. And providing an image forming system.

In order to achieve the above object, a post-processing apparatus according to the present invention includes a pair of folding rollers pressed against each other, and a comb tooth portion in which concave portions and convex portions are continuously formed in the axial direction of the pair of folding rollers. The comb teeth portion is inserted between the pair of folding rollers together with the paper, so that a folding knife that folds the paper, a paper width aligning portion that guides the paper to a predetermined width direction, Width information which is information on the position of both ends of the sheet detected by the detecting means for detecting the position of both ends of the sheet or the width of the sheet in the axial direction is input by the sheet width matching unit When inserting the comb teeth of the folding knife together with the paper guided to a predetermined position in the width direction between the pair of folding rollers , at each of both ends of the guided paper, Folding knife And a control unit for controlling such that the distance decreases between the end nearest the convex portion in the paper inward than portions of parts, the folding knife, on its both ends, the which has the convex portion It has a plate that slides in the axial direction, and is configured to be able to expand and contract in the axial direction by sliding movement of the plate on both ends. The control unit slides the plate on both ends based on the width information. In each of the both ends of the guided sheet , the distance between the end of the sheet and the convex part closest to the end of the folding knife in the inner side of the sheet is reduced. .

According to this post-processing apparatus, since the folding knife has the comb-tooth portion in which the concave portion and the convex portion are continuously formed, the load in the insertion / extraction between the pair of folding rollers is reduced. Further, when inserting the comb tooth portion of the folding knife between the pair of folding rollers, the both ends of the paper in the axial direction and the convex portion closest to the inner side of both ends of the paper among the convex portions of the folding knife. Since the distance is controlled so as to decrease, it is possible to prevent a situation in which the distance between the both end portions of the sheet and the convex portion becomes too large, and the entry timing of the end portion of the sheet is greatly delayed from the other portions. Therefore, it is possible to reduce the driving load of the folding knife and prevent the paper from being wrinkled or torn. Furthermore, by extending and retracting the folding knife in the axial direction, the distance between the both ends of the paper and the convex portion closest to the inside is reduced. Even when both ends of the paper are cut by the processing, the convex portions can be appropriately positioned according to the cut amount.

In order to achieve the above object, a post-processing apparatus according to the present invention includes a pair of folding rollers that are pressed against each other and a comb in which concave portions and convex portions are continuously formed in the axial direction of the pair of folding rollers. A folding knife that has teeth and folds the sheet by inserting the comb teeth between the pair of folding rollers together with the sheet; and a sheet width alignment unit that guides the sheet to a predetermined position in the width direction. , Input the width information that is the width of the sheet in the axial direction, or the width information that is the position information of both ends of the sheet detected by the detecting means that detects the positions of both ends of the sheet, When the comb tooth portion of the folding knife is inserted between the pair of folding rollers together with the sheet guided to a predetermined width direction position by the section, the end of the sheet at each of both ends of the guided sheet And the above folding And a control unit that controls the distance between the convex portion closest to the end portion in the paper inner direction from the end portion, and the folding knife has the convex portion at least on one end side. And a plate member that slides in the axial direction, and is configured to be extendable and contractible in the axial direction by sliding movement of the plate member on at least one end side, and the control unit controls the paper width aligning unit to The sheet is guided by guiding the sheet so that the distance between the other end and the convex part on the other end of the folding knife is reduced, and sliding the plate on the one end based on the width information. It controls so that the distance of the one edge part of this and the convex part of the said board | plate material of one end side may decrease.

According to this post-processing apparatus, since the folding knife has the comb-tooth portion in which the concave portion and the convex portion are continuously formed, the load in the insertion / extraction between the pair of folding rollers is reduced. Further, when inserting the comb tooth portion of the folding knife between the pair of folding rollers, the both ends of the paper in the axial direction and the convex portion closest to the inner side of both ends of the paper among the convex portions of the folding knife. Since the distance is controlled so as to decrease, it is possible to prevent a situation in which the distance between the both end portions of the sheet and the convex portion becomes too large, and the entry timing of the end portion of the sheet is greatly delayed from the other portions. Therefore, it is possible to reduce the driving load of the folding knife and prevent the paper from being wrinkled or torn. Furthermore, in order to reduce the distance between both end portions of the paper and the closest convex portion in the inner direction by expanding and contracting only one end side of the folding knife, for example, the other end portion of the paper is attached to the convex portion on the other end side of the folding knife. It can be adjusted by extending and contracting only one end side.

  In the post-processing apparatus according to the present invention, the control unit includes at least one of paper basis weight, number of sheets to be folded, presence of crease, paper conveyance direction after folding, and insertion amount of the folding knife. It is preferable to set the predetermined distance according to information.

  According to this post-processing apparatus, the predetermined distance is set according to the basis weight of the paper, the number of sheets to be folded, the presence or absence of crease, the paper conveyance direction after folding, and the insertion amount of the folding knife. Here, the basis weight of the paper is also a value indicating the strength of the paper, and greatly affects wrinkles and tears. Further, when the number of stacked sheets increases, wrinkles and tears are less likely to occur. Further, the sheet strength is reduced at the crease portion. When the folded paper passes between a pair of folding rollers, or when the insertion amount of the folding knife is increased, wrinkles and tears tend to occur. Therefore, wrinkles and tears can be prevented more appropriately by setting the predetermined distance based on these at least one piece of information.

  An image forming system according to the present invention includes the post-processing device according to any one of the above, and an image forming device that forms an image on a sheet and supplies the image to the post-processing device. Features.

  According to the image forming system of the present invention, it is possible to provide an image forming system capable of reducing the driving load of the folding knife and preventing the paper from being wrinkled or torn.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing the drive load of a folding knife, the post-processing apparatus which can prevent a wrinkle and tear of a paper can be provided.

1 is a schematic configuration diagram illustrating an image forming system including a sheet post-processing apparatus according to a first embodiment. FIG. 2 is a side view illustrating a configuration of a sheet folding unit illustrated in FIG. 1. FIG. 2 is a top view illustrating a partial configuration of a sheet folding unit illustrated in FIG. 1. It is a block diagram which shows the staple part shown in FIG. It is a block diagram which shows the detail of the folding knife shown in FIG. 2, Comprising: (a) has shown the top view, (b) has shown the top view. It is a top view of the folding knife shown in FIG. 2, Comprising: The example in case paper width is small is shown. It is a top view of the folding knife shown in FIG. 2, Comprising: The example in case a paper width is large is shown. It is a figure which shows the predetermined distance for preventing the wrinkle and tear of a paper. It is a flowchart which shows operation | movement of the post-processing apparatus which concerns on 1st Embodiment. It is a top view which shows the folding knife which concerns on 2nd Embodiment. FIG. 10 is a top view illustrating a paper standby path according to a third embodiment. It is a schematic plan view for demonstrating the cause of wrinkle generation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

  FIG. 1 is a schematic configuration diagram illustrating an image forming system including a sheet post-processing apparatus according to the first embodiment. An image forming system 1 illustrated in FIG. 1 includes an image forming apparatus A and a post-processing apparatus B that performs post-processing on a sheet S on which an image is formed by the image forming apparatus A.

  The image forming apparatus A is a tandem color type that forms a full-color image on the paper S by arranging a plurality of photoconductors facing a single intermediate transfer belt in the vertical direction, 1 includes an image reading device 2 including an automatic document feeder and a scanning exposure device, and includes an image forming unit 3 and a plurality of paper feed trays 4 at a lower portion.

  The image reading device 2 transports a document placed on a document tray of an automatic document transport device by a transport unit, scans and exposes an image on one or both sides of the document, and reads image information. The image reading device 2 is also configured to read image information of a document placed on the contact glass.

  The image forming unit 3 receives the supply of paper S from a plurality of paper feed trays 4 and is based on image information read by the image reading device 2 or image information transmitted from a PC (personal computer) or the like. Thus, an image is formed on the paper S.

  The image forming unit 3 includes an image transfer unit 3a and a fixing unit 3b. The image transfer unit 3a forms a toner image on the photosensitive member by an electrophotographic process that performs charging, exposure, and development, and transfers the image to the paper S. In the first embodiment, the image transfer unit 3a is of a type having an intermediate transfer belt. Toner images on a plurality of photoreceptors are transferred to the intermediate transfer belt, and the toner images on the intermediate transfer belt are transferred to the paper S. Is done.

  The fixing unit 3b forms a nip portion that transports the paper S with a heating roller and a pressure roller, melts the toner by heating and pressurizing while transporting the paper S, and transfers the toner onto the paper S by the image transfer unit 3a. The printed image is fixed on the paper S.

  Further, the image forming apparatus A includes a reversing path 5 that leads from the downstream side of the fixing unit 3b to the upstream side of the image transfer unit 3a. The reverse path 5 is a path for re-transporting the paper S to the image transfer unit 3a after reversing the front and back of the paper S. By this reversal path 5, front and back images can be formed on the paper S.

  The post-processing apparatus B according to the first embodiment includes a paper folding function and a stapling function. In addition, although illustration is abbreviate | omitted, the post-processing apparatus B may be provided with a punch function, a humidification function, etc. other than the said function. As shown in FIG. 1, such a post-processing apparatus B includes a post-processing unit Af having a sheet folding unit 10 and a stapling unit 20, a control unit 30, various paths R1 to R3, and a paper discharge tray Tr1, Tr2 is provided.

  The first path R1 is a path for receiving the sheet S from the image forming apparatus A and conveying the received sheet S to the post-processing unit Af. The second path R2 is a path for guiding the sheet bundle that has passed through the sheet folding unit 10 and the stapling unit 20 of the post-processing unit Af to the first sheet discharge tray Tr1. The third path R3 is a path for guiding the sheet S folded in three by the sheet folding unit 10 of the post-processing unit Af to the second sheet discharge tray Tr2 without passing through the staple unit 20.

  The sheet folding unit 10 is a mechanism unit for folding one or a plurality of sheets S. 2 is a side view showing the configuration of the paper folding unit 10 shown in FIG. 1, and FIG. 3 is a top view showing a partial configuration of the paper folding unit 10 shown in FIG.

  As shown in FIG. 2, the sheet folding unit 10 includes three folding rollers Fr1 to Fr3, two folding knives Fn1 and Fn2, a sheet standby path Sr, and a sheet end alignment unit Sea.

  The sheet standby path Sr is a conveyance path that receives one or a plurality of sheets S from the first path R1 and waits. The sheet end alignment unit Sea aligns the front ends of the sheets S received in the sheet standby path Sr. The sheet edge aligning portion Sea includes a contact portion Cp, two rollers r1 and r2, and a belt b. The contact portion Cp is a member that is positioned on the front end side of the paper standby path Sr and contacts the front end of the conveyed paper S to align the paper S. The belt b is an endless belt that is wound around two rollers r1 and r2. A contact portion Cp is attached to the belt b. For this reason, when the two rollers r1 and r2 are driven to rotate and the belt b travels, the contact portion Cp also moves in the front-rear direction in the paper standby path Sr in conjunction with this.

  The three folding rollers Fr1 to Fr3 are pressed against each other to form nip portions N1 and N2 at two locations. The two folding knives Fn1 and Fr2 are plate-like members inserted between the folding rollers Fr1 to Fr3 together with one or a plurality of sheets S.

  More specifically, the first folding knife Fn1 is a pair of folding rollers that form the first nip portion N1 together with one or more sheets S that are received in the sheet standby path Sr and aligned at the sheet end alignment section Sea. It is inserted between Fr1 and Fr2. With this insertion, the paper S is creased. When the sheet S is folded in three when the first folding knife Fn1 is inserted, the sheet S is opposite to the installation position of the first folding knife Fn1 by driving the pair of folding rollers Fr1 and Fr2 ( That is, the sheet is conveyed to the side opposite to the sheet standby path Sr and on the installation side of the second folding knife Fn2. On the other hand, when the folded sheet S is supplied to the staple unit 20 without being folded in three, the pair of folding rollers Fr1 and Fr2 drives the first folding knife Fn1 (that is, the sheet standby path Sr side). ) And then to the staple unit 20.

  The second folding knife Fn2 is inserted between the pair of folding rollers Fr2 and Fr3 that form the second nip portion N2 together with the paper S once folded by the pair of folding rollers Fr1 and Fr2 and the first folding knife Fn1. It is what is done. By this insertion, the sheet S is folded and is folded in three. The three-folded paper S is conveyed to the side opposite to the installation position of the second folding knife Fn2 by driving the pair of folding rollers Fr2 and Fr3, and is discharged to the second paper discharge tray Tr2 through the third path R3.

  As shown in FIG. 3, the sheet folding unit 10 includes a sheet width matching unit Swa in addition to the above configuration. The paper width alignment unit Swa aligns the paper S received in the paper standby path Sr so that it is aligned in the width direction of the paper S.

  The sheet width aligning section Swa includes, for example, two guide members G1 and G2 extending on the inner side and the front end side of the sheet waiting path Sr. For example, the sheet S received in the sheet waiting path Sr with a deviation in the sheet width direction. 'Is guided to a predetermined position in the width direction. With such a configuration, the sheet S is aligned and folded in the width direction.

  In addition, it is preferable that the sheet width alignment unit Swa is configured so that the two guide members G1 and G2 can operate so as to correspond to various sheet widths. For example, as shown in FIG. 3, when a sheet S having a small sheet width is received, the sheet S is moved to a predetermined position in the width direction by rotating the two guide members G1 and G2 toward each other. It is preferable to induce.

  FIG. 4 is a configuration diagram illustrating the staple unit 20 illustrated in FIG. 1. As shown in FIG. 4, the staple unit 20 is provided in the forward direction of the sheet folding unit 10 (the direction of the arrow a1 shown in FIG. 4), and is a mechanism unit that holds a plurality of sheets S with staples. Such a staple unit 20 includes a paper placement unit 21 and a stapler 22.

  The paper stacking unit 21 receives and stacks a bundle of papers S folded by the paper folding unit 10. The stapler 22 performs a stapling process on a portion of the bundle of sheets S placed on the sheet placement unit 21 that has a crease. The movement of the paper S from the paper folding unit 10 to the paper stacking unit 21 is performed by a predetermined transport unit (not shown). In addition, the bundle of sheets S stacked on the sheet placement unit 21 can move in the direction of the arrow a1, or the stapler 22 can move in the depth direction, and the staple unit 20 is 1 on the fold line. Alternatively, stapling can be performed at a plurality of positions.

  FIG. 5 is a configuration diagram showing details of the folding knives Fn1 and Fn2 shown in FIG. 2, wherein (a) shows a plan view and (b) shows a top view. First, as shown in FIG. 5A, the folding knives Fn1 and Fn2 are formed with the concave portions 41 and the convex portions 42 continuously in the axial direction of the folding rollers Fr1 to Fr3 (the depth direction shown in FIG. 4). A comb tooth portion 40 is provided. Such a comb tooth portion 40 is inserted into the nip portions N1 and N2. For this reason, the driving load of the folding knives Fn1 and Fn2 when the folding knives Fn1 and Fn2 are inserted and pulled out is reduced.

  The folding knives Fn1 and Fn2 include first to third plate members P1 to P3 and two guide rods Gb1 and Gb2, and are configured to be extendable and contractable in the axial direction of the folding rollers Fr1 to Fr3.

  The 1st board | plate material P1 is a site | part used as the main body of folding knife Fn1, Fn2, Comprising: The three convex part 42 and the two recessed part 41 pinched | interposed by these are formed continuously. In addition, two guide rods Gb1 and Gb2 are attached to the first plate P1 so as to penetrate the plate surface and be separated from each other in the roller axis direction.

  The second plate member P2 and the third plate member P3 are configured symmetrically with the first plate member P1 sandwiched therebetween, each having one convex portion 42a on the end side in the roller axis direction, and the other portion being the concave portion 41. It is an L-shaped plate material. Furthermore, the second plate material P2 and the third plate material P3 are formed with guide grooves GS1, GS2 extending in the roller axis direction, and the guide rods Gb1, Gb2 of the first plate material P1 are inserted into the guide grooves GS1, GS2. ing. For this reason, when the guide rods Gb1 and Gb2 slide in the guide grooves GS1 and GS2, the second plate member P2 and the third plate member P3 are movable in the roller axis direction. For this reason, also about the one convex part 42a provided in the 2nd board | plate material P2 and the 3rd board | plate material P3, it can move to a roller axial direction, and the position of the convex part 42a can be adjusted.

  Further, as shown in FIG. 5B, the second plate material P2 and the third plate material P3 have a bent portion FP that is bent at the formation position of the concave portion 41 when viewed from above, and the convex portion 42a It is located on the same plane as the convex portion 42 of one plate material P1. As a result, the crease is not formed in two steps with respect to the paper S, but is formed in a straight line.

  Refer to FIG. 1 again. The control unit 30 controls the entire post-processing apparatus B. The control unit 30 is also configured to communicate with the control unit 6 of the image forming apparatus A, and acquires information necessary for controlling the post-processing apparatus B from the image forming apparatus A.

  In particular, in this embodiment, the control unit 30 inserts the comb teeth 40 of the folding knives Fn1 and Fn2 between the folding rollers Fr1 to Fr3, both ends of the sheet S in the roller axis direction, and the folding knives Fn1 and Fn2. The folding knives Fn1 and Fn2 are controlled to be expanded and contracted so that the distance from the convex portions 42a on both ends is within a predetermined distance. The positions of both ends of the sheet S are determined by the control unit 30 from the sheet width information.

  FIG. 6 is a plan view of the folding knives Fn1 and Fn2 shown in FIG. 2 and shows an example in which the paper width is small. As shown in FIG. 6, the control unit 30 compresses the folding knives Fn1 and Fn2 in accordance with the small sheet width. Thereby, both ends of the paper S are located on the convex portions 42a of the folding knives Fn1 and Fn2. Thereby, it can prevent that the rush timing of the both ends of the paper S with respect to the folding rollers Fr1-Fr3 is delayed rather than another part, and the wrinkle and tearing of the paper S can be prevented.

  FIG. 7 is a plan view of the folding knives Fn1 and Fn2 shown in FIG. 2 and shows an example in which the paper width is large. As shown in FIG. 7, the control unit 30 extends the folding knives Fn1 and Fn2 in accordance with the large sheet width. Here, in the example shown in FIG. 7, both end portions of the paper S are in a state of protruding from the convex portions 42a of the folding knives Fn1 and Fn2. As described above, the both ends of the paper S are not limited to be located on the convex portion 42a, and even if they slightly protrude, the protruding amount (the convex portions on the both ends of the paper S and the both ends of the folding knives Fn1, Fn2) If the distance 42a is within a predetermined distance, it is possible to prevent the entry timing of both ends of the paper S from being delayed from the other parts, and to prevent the paper S from being wrinkled or torn.

  Here, the predetermined distance varies depending on the paper conditions. For example, the paper S having a strong stiffness may have a longer predetermined distance, and the paper S having a weak stiffness may have a shorter predetermined distance.

  FIG. 8 is a diagram illustrating a predetermined distance for preventing the paper S from being wrinkled or torn. The control unit 30 stores data as shown in FIG. 8, for example. This data indicates, for example, a predetermined distance when folding a single sheet S. In this data, for example, when the basis weight of the paper S is 50 gsm, 60 gsm, and 70 gsm, the paper S is not wrinkled or torn even if the protrusion amount of the paper S is 5 mm, but when the protrusion amount is 10 mm, the paper S It shows that wrinkles and tears occur. Therefore, when folding one sheet S having a basis weight of 50 gsm, 60 gsm, or 70 gsm, the control unit 30 expands and contracts the folding knives Fn1 and Fn2 so that the protruding amount is within 5 mm.

  Similarly, when folding one sheet S having a basis weight of 80 gsm and 90 gsm, the control unit 30 expands and contracts the folding knives Fn1 and Fn2 so that the protruding amount is within 10 mm, and the basis weight is 100 gsm. When folding one sheet S of 110 gsm, the folding knives Fn1 and Fn2 are expanded and contracted so that the amount of protrusion is within 15 mm. Similarly, the folding knives Fn1 and Fn2 are expanded and contracted so that the protruding amount is within the predetermined distance shown in FIG. 8 for the basis weight of 120 gsm or more.

  FIG. 9 is a flowchart showing the operation of the post-processing apparatus B according to the first embodiment. As shown in FIG. 9, when an operation to fold the sheet S is performed on the image forming apparatus A, the control unit 30 of the post-processing apparatus B receives the sheet width information from the control unit 6 of the image forming apparatus A. Input (S1). The paper width information input here is not only the paper size information such as A4 and B5, but is cut when the orientation of the paper S and both ends of the paper S are cut. It also includes information such as width. Further, in step S1, either one of the post-processing apparatus B and the image forming apparatus A is provided with a sensor for detecting the positions of both ends of the sheet S, and information from this sensor is input. Good.

  Next, the control unit 30 of the post-processing apparatus B inputs the basis weight information of the paper S from the control unit 6 of the image forming apparatus A (S2). And the control part 30 sets the allowable value of the protrusion amount, ie, a predetermined distance, based on the information input in step S2 and the data as shown in FIG. 8 (S3). In the present embodiment, the predetermined distance is set based only on the basis weight, but not limited thereto, for example, the number of sheets S to be folded, the presence or absence of crease, the conveyance direction of the folded sheets, and The predetermined distance may be set according to at least one piece of information about the folding knives Fn1 and Fn2. This is because wrinkles and tears are less likely to occur when the number of stacked sheets S increases. In addition, the strength of the paper at the crease portion is reduced, and wrinkles and tears are less likely to occur. Furthermore, when the folded sheet S passes between the folding rollers Fr1 to Fr3 or when the insertion amount of the folding knives Fn1 and Fn2 is increased, wrinkles and tears tend to occur.

  Next, the control unit 30 expands and contracts the folding knives Fn1 and Fn2 so that the amount of protrusion of the paper S is within the predetermined distance set in step S3 (S4). Accordingly, when the folding knives Fn1 and Fn2 are inserted between the folding rollers Fr1 to Fr3 together with the paper S, it is possible to prevent the paper S from being wrinkled or torn.

  Thus, according to the post-processing apparatus B and the image forming system 1 according to the first embodiment, the folding knives Fn1 and Fn2 have the comb teeth portion 40 in which the concave portion 41 and the convex portion 42 are continuously formed. Therefore, the load in insertion / extraction between the folding rollers Fr1 to Fr3 is reduced. Further, when inserting the comb teeth 40 of the folding knives Fn1 and Fn2 between the folding rollers Fr1 to Fr3, a distance L between the both ends of the sheet S and the convex portions 42a of the folding knives Fn1 and Fn2 is predetermined. Since the distance L is controlled to be within the distance, it is possible to prevent a situation in which the distance L between the both end portions of the sheet and the convex portion 42a becomes too large and the entry timing of the end portion of the sheet is greatly delayed from the other portions. it can. Therefore, it is possible to reduce the driving load of the folding knives Fn1 and Fn2 and to prevent the paper from being wrinkled or torn.

  Further, by extending and contracting the folding knives Fn1 and Fn2 in the roller axis direction, the distance L between the both ends of the sheet S and the convex portion 42a is within a predetermined distance. For example, even when both ends of the paper S are cut in the preprocessing, the convex portion 42a can be appropriately positioned according to the cut amount.

  Further, since the control is performed based on the sheet width that is the length of the sheet S in the roller axis direction or the detected position information of both ends of the sheet S, the distance L between the both ends of the sheet and the convex portion 42a is a predetermined distance. It is possible to control appropriately within the range.

  The predetermined distance is set according to the basis weight of the paper S, the number of sheets S to be folded, the presence or absence of crease, the paper transport direction after folding, and the insertion amount of the folding knives Fn1 and Fn2. Here, the basis weight of the paper S is also a value indicating the stiffness of the paper S, and greatly affects wrinkles and tears. Further, when the number of stacked sheets S increases, wrinkles and tears are less likely to occur. Further, the sheet strength is reduced at the crease portion. When the folded sheet S passes between the folding rollers Fr1 to Fr3 or when the insertion amount of the folding knives Fn1 and Fn2 is increased, wrinkles and tears tend to occur. Therefore, wrinkles and tears can be prevented more appropriately by setting the predetermined distance based on these at least one piece of information.

  In the first embodiment, the control unit 30 controls the distance between the both ends of the sheet S in the roller axis direction and the protrusions 42a on the both ends of the folding knives Fn1 and Fn2 to be within a predetermined distance. ing. However, the present invention is not limited to this, and the control unit 30 has a predetermined distance between both ends of the sheet S and the protrusions 42 of the folding knives Fn1 and Fn2 that are closest to the both ends of the sheet S in the inner direction. You may control so that it may be less than a distance. That is, the convex portion 42 closest to the both ends of the paper S is not limited to the convex portion 42a on the both end sides of the folding knives Fn1 and Fn2. For this reason, for example, the control unit 30 controls the distance between the both ends of the sheet S and the convex portion 42b (see FIG. 5A) located inside the convex portion 42a to be within a predetermined distance. May be.

  In addition, in the first embodiment, the folding knives Fn1 and Fn2 can be adjusted only for the positions of the convex portions 42a on both ends. However, the present invention is not limited to this, and other convex portions such as the inner convex portions 42b can be used. The position of the part 42 may also be configured to be adjustable.

  Next, a second embodiment of the present invention will be described. The post-processing apparatus and the image forming system according to the second embodiment are the same as those of the first embodiment, but the configuration and processing contents are partially different. Hereinafter, differences from the first embodiment will be described.

  FIG. 10 is a plan view showing folding knives Fn1 and Fn2 according to the second embodiment. As shown in FIG. 10, in the second embodiment, the folding knives Fn1 and Fn2 are configured by a plurality (three) of individual knives K1 to K3 arranged with the positions of the convex portions 42 being different in the roller axis direction. Yes.

  Since the folding knives Fn1 and Fn2 are provided, the control unit 30 selects any one of the plurality of individual knives K1 to K3, and folds the comb teeth 40 of the selected individual knives K1 to K3. Insert between rollers Fr1 to Fr3. As a result, the control unit 30 determines the distance between the both ends of the sheet S in the roller axis direction and the protrusions 42 of the selected individual knives K1 to K3 (the protrusions 42 closest to the inner side of both ends of the sheet S). Is within a predetermined distance.

  More specifically, the control unit 30 selects an individual knife K1 for a certain sheet S, and sets the convex portion 42 closest to the inner side of both ends of the sheet S to one end side of the individual knife K1. The convex portion 42c and the second convex portion 42d from the other end side are selected. For some other paper S, the individual knife K2 is selected, and the convex portion closest to the inner side of both ends of the paper S is selected. 42 is controlled to be a convex portion 42a on both ends of the individual knife K2.

  In the example shown in FIG. 10, the plurality of individual knives K <b> 1 to K <b> 3 are all the same shape, but are not limited thereto, and may be different shapes. In particular, if the individual knives K1 to K3 are configured to have different distances between the convex portions 42a on both ends, appropriate individual knives K1 to K3 can be easily selected according to the paper width.

  As described above, according to the post-processing apparatus B and the image forming system 1 according to the second embodiment, the driving load of the folding knives Fn1 and Fn2 is reduced and the paper is wrinkled or torn as in the first embodiment. Can be prevented. Further, it is possible to appropriately control the distance L between the both end portions of the sheet and the convex portion 42 within a predetermined distance. Furthermore, by setting the predetermined distance based on at least one piece of information such as the basis weight of the paper S, wrinkles and tears can be more appropriately prevented.

  Further, according to the second embodiment, any one of the plurality of individual knives K1 to K3 is selected, and the comb tooth portion 40 of the selected individual knives K1 to K3 is inserted between the folding rollers Fr1 to Fr3. By doing so, the distance L between the both ends of the paper S and the convex portions 42 of the selected individual knives K1 to K3 is set within a predetermined distance. In this way, the folding knives Fn1 and Fn2 are configured by a plurality of individual knives K1 to K3 having different positions of the convex portions 42, so that a mechanism for fine adjustment is not required and a plurality of individual knives K1 to It is only necessary to operate any one of K3, and it is possible to prevent the paper from being wrinkled or torn without adopting a relatively complicated configuration.

  Next, a third embodiment of the present invention will be described. The post-processing apparatus and the image forming system according to the third embodiment are the same as those of the first embodiment, but the configuration and processing contents are partially different. Hereinafter, differences from the first embodiment will be described.

  FIG. 11 is a top view showing the sheet standby path Sr according to the third embodiment. In the first embodiment, the two guide members G1 and G2 provided in the paper standby path Sr are movable, and the control unit 30 allows the paper S to be in the same position regardless of the paper width ( That is, the guide is performed so that the center line of the sheet S is at the same position. For this reason, the two guide members G1 and G2 operate symmetrically so as to approach or separate from each other.

  On the other hand, in the third embodiment, the two guide members G1 and G2 can adjust the position of the paper S in the axial direction. That is, the control unit 30 adjusts the position of the center line of the paper S in the paper width direction (roller axis direction), and among the both ends of the paper S in the roller axis direction and the convex portions 42 of the folding knives Fn1 and Fn2, The distance from the convex portion 42 closest to the inner side direction of both end portions is set within a predetermined distance.

  As described above, according to the post-processing apparatus B and the image forming system 1 according to the third embodiment, the driving load of the folding knives Fn1 and Fn2 is reduced and the paper is wrinkled or torn as in the first embodiment. Can be prevented. Further, it is possible to appropriately control the distance L between the both end portions of the sheet and the convex portion 42 within a predetermined distance. Furthermore, by setting the predetermined distance based on at least one piece of information such as the basis weight of the paper S, wrinkles and tears can be more appropriately prevented.

  Furthermore, according to the third embodiment, by adjusting the paper position in the roller axis direction, the distance L between the both ends of the paper S and the convex portion 42 is within a predetermined distance, so that the folding knives Fn1, Fn2, etc. For the mechanism, a conventional mechanism can be used.

  As described above, the image forming apparatus according to the present invention has been described based on the embodiment. However, the present invention is not limited to this, and modifications may be made without departing from the spirit of the present invention. If so, the techniques described in the embodiments may be combined.

  For example, the first embodiment and the third embodiment may be combined as follows. That is, the folding knives Fn1 and Fn2 are configured to be extendable and contracted, and only one end side of the folding knives Fn1 and Fn2 may be expanded and contracted to be within a predetermined distance. In this case, the control unit 30 controls the two guide members G1 and G2 as in the third embodiment, for example, so that the other end side of the sheet S is within a predetermined distance from the convex portion 42a. Induce. Next, the control unit 30 expands and contracts only one end side of the folding knives Fn1 and Fn2 so that the distance between the sheet end portion and the convex portion 42a is within a predetermined distance. In this way, only one end side of the folding knives Fn1 and Fn2 may be expanded and contracted to prevent the paper S from being wrinkled or torn. In this case, the folding knives Fn1 and Fn2 may not be extendable at both ends, and may be configured to be extendable only at one end.

  Further, in the above-described embodiment, the post-processing apparatus B is not limited to the apparatus connected to the subsequent stage of the image forming apparatus A, but is an off-line finisher that is not connected to the image forming apparatus A and performs post-processing on the sheet S after image formation alone. May be applied. In this case, the offline finisher may be provided with means for acquiring information such as the paper width and basis weight of the paper S.

1: Image forming system 10: Paper folding unit 20: Staple unit 21: Paper placement unit 22: Stapler 30: Control unit 40: Comb portion 41: Concave portion 42, 42a, 42b: Convex portion A: Image forming apparatus B: Post-processing devices Fn1, Fn2: folding knives Fr1-Fr3: folding rollers K1-K3: individual knives S: paper

Claims (3)

A pair of folding rollers pressed against each other;
A pair of folding rollers, each of which has a comb-tooth portion formed with a concave portion and a convex portion continuously in the axial direction, and the comb-tooth portion is inserted between the pair of folding rollers together with the paper. A folding knife to crease,
A paper width alignment unit for guiding the paper to a predetermined position in the width direction;
The width of the sheet, which is the length of the sheet in the axial direction, or width information that is information on the positions of both ends of the sheet detected by the detecting means that detects the positions of both ends of the sheet is input, and the sheet width matching unit When the comb tooth portion of the folding knife is inserted between the pair of folding rollers together with the paper guided to a predetermined position in the width direction by the edge of the paper at each of both ends of the guided paper, and a control unit for controlling such that the distance is reduced to the nearest protrusions in the paper inward direction from the end portion of the convex portion of the folding knife,
The folding knife has a plate member that slides in the axial direction and has the convex portions on both end sides thereof, and is configured to be extendable and contractible in the axial direction by sliding movement of the plate member on both end sides,
The control unit slides the plate members on both ends based on the width information, and at each of the both ends of the guided paper, from the end of the paper edge and the convex part of the folding knife. Also reduce the distance to the nearest convex part in the paper inner direction
Post-processing apparatus, characterized in that. A pair of folding rollers pressed against each other;
A pair of folding rollers, each of which has a comb-tooth portion formed with a concave portion and a convex portion continuously in the axial direction, and the comb-tooth portion is inserted between the pair of folding rollers together with the paper. A folding knife to crease,
A paper width alignment unit for guiding the paper to a predetermined position in the width direction;
The width of the sheet, which is the length of the sheet in the axial direction, or width information that is information on the positions of both ends of the sheet detected by the detecting means that detects the positions of both ends of the sheet is input, and the sheet width matching unit When the comb tooth portion of the folding knife is inserted between the pair of folding rollers together with the paper guided to a predetermined position in the width direction by the edge of the paper at each of both ends of the guided paper, and a control unit for controlling such that the distance is reduced to the nearest protrusions in the paper inward direction from the end portion of the convex portion of the folding knife,
The folding knife has a plate member that slides in the axial direction while having the convex portion at least on one end side, and is configured to be expandable and contractable in the axial direction by sliding movement of the plate material on at least one end side,
The control unit controls the sheet width matching unit to guide the sheet so that the distance between the other end of the sheet and the convex part on the other end of the folding knife is reduced, and the width information said plate at one end is slid, controls so that the distance between the convex portion of the plate one end of the induced sheet and one end side is reduced on the basis of
Post-processing apparatus, characterized in that. A post-processing device according to claim 1 or 2 ,
An image forming apparatus that forms an image on a sheet and supplies the image to the post-processing apparatus;
An image forming system comprising:

Images